Mobile phone with an antenna structure having improved performance

ABSTRACT

A mobile phone with a FM antenna structure having improved FM performance in a mobile phone. The mobile phone includes a printed FM antenna having a planar structure less than a planar area of the mobile phone, a conductive layer providing a ground plane to the printed FM antenna, the conductive adjacent the printed FM antenna in an electrostatic field relation; and a battery having a planar surface positioned adjacent an opposite side of the conductive layer. The planar structure of the printed FM antenna and the planar surface of the battery are substantially parallel to each other in a spaced-apart relation improving the FM performance of the printed FM antenna.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 60/889,528 entitled “Mobile Phone with an Antenna Structure havingImproved Performance,” filed Feb. 12, 2007, which is hereby incorporatedherein by reference in its entirety for all purposes.

SPECIFICATION

1. Technical Field

The present invention relates to wireless communications and, moreparticularly, signal reception and transmission in mobile wirelesscommunication systems.

2. Related Art

Communication systems are known to support wireless and wire linedcommunications between wireless and/or wire lined communication devices.Such communication systems range from national and/or internationalcellular telephone systems to the Internet to point-to-point in-homewireless networks. Each type of communication system is constructed, andhence operates, in accordance with one or more communication standards.For instance, wireless communication systems may operate in accordancewith one or more standards, including, but not limited to, IEEE 802.11,Bluetooth, advanced mobile phone services (AMPS), digital AMPS, globalsystem for mobile communications (GSM), code division multiple access(CDMA), local multi-point distribution systems (LMDS),multi-channel-multi-point distribution systems (MMDS), and/or variationsthereof.

Depending on the type of wireless communication system, a wirelesscommunication device, such as a mobile telephone, two-way radio,personal digital assistant (PDA), personal computer (PC), laptopcomputer, home entertainment equipment, et cetera, communicates directlyor indirectly with other wireless communication devices. For directcommunications (also known as point-to-point communications), theparticipating wireless communication devices tune their receivers andtransmitters to the same channel or channels (for example, one of aplurality of radio frequency (RF) carriers of the wireless communicationsystem) and communicate over that channel(s). For indirect wirelesscommunications, each wireless communication device communicates directlywith an associated base station (for example, for cellular services)and/or an associated access point (for example, for an in-home orin-building wireless network) via an assigned channel. To complete acommunication connection between the wireless communication devices, theassociated base stations and/or associated access points communicatewith each other directly, via a system controller, via a public switchtelephone network (PSTN), via the Internet, and/or via some other widearea network.

Each wireless communication device includes a built-in radio transceiver(that is, a receiver and a transmitter) or is coupled to an associatedradio transceiver (for example, a station for in-home and/or in-buildingwireless communication networks, RF modem, et cetera). As is known, thetransmitter includes a data modulation stage, one or more intermediatefrequency stages, and a power amplifier stage. The data modulation stageconverts raw data into baseband signals in accordance with theparticular wireless communication standard. The one or more intermediatefrequency stages mix the baseband signals with one or more localoscillations to produce RF signals. The power amplifier stage amplifiesthe RF signals prior to transmission via an antenna.

An antenna is an essential element for a wireless communication device.The antenna provides a wireless interface for the wireless communicationdevice, which may be a radio, mobile phone, pager, station (for wirelesslocal area network, wireless internet, et cetera). The particular typeof wireless communication system, which prescribes the transmissionfrequencies, reception frequencies and power levels, dictates theperformance requirements for the antenna.

Because most wireless communication devices are handheld or portabledevices, each component comprising these devices must be small,efficient, economical and lightweight. The antenna is no exception—ittoo must be small, efficient, economical and lightweight. To achievethese requirements, many antennas have been developed having variousstructures including monopole, dipole, et cetera.

The diminutive size of the antennas, however, leave them moresusceptible to environmental changes that correspondingly affect theability of an antenna to reliably receive and/or transmit signals. Forexample, mobile phones can be readily held within the grasp of a user,or placed within a pocket, et cetera. When environmental conditionschange, the impedance and consequently the ability of the antenna areadversely affected, reducing the signal-to-noise performance of theantenna.

Although favorable environmental conditions may return, a user becomesfrustrated by the inconsistency of the service for their mobile phone ordevice. Also, the compactness of mobile wireless devices can cause E-Minterference between other device components, further degrading antennaperformance. Accordingly, various types of antennas and correspondingshapes provide adequate antenna performance. Nevertheless, they becomebecoming increasingly sensitive to environmental changes andinterference from other device components. Therefore, a need exists fora printed antenna structure for a mobile phone that improves theperformance of the increasingly sensitive antennae in such adverseenvironmental conditions.

SUMMARY

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Drawings, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the drawings madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiment is consideredwith the following drawings, in which:

FIG. 1 is a functional block diagram illustrating a communication systemthat includes a plurality of base stations or access points (APs), aplurality of wireless communication devices and a network hardwarecomponent;

FIG. 2 is a schematic block diagram illustrating a wirelesscommunication device architecture including an FM transceiver and an FMantenna tuning module according to an embodiment of the presentinvention;

FIG. 3 is a schematic block diagram illustrating a wirelesscommunication device architecture including an FM transceiver an FMantenna tuning module coupled with a tuning circuit according to anembodiment of the present invention;

FIG. 4 is an exploded view of a mobile phone with a brick configurationthat includes an antenna structure according to an embodiment of thepresent invention;

FIG. 5 is an exploded view of a mobile phone with a clamshellconfiguration that includes an antenna structure according to anembodiment of the present invention;

FIG. 6 is a cross-sectional diagram of an antenna structure including aprinted FM antenna in a first orientation according to an embodiment ofthe present invention;

FIG. 7 is a cross-sectional diagram of an antenna structure including aprinted FM antenna in a second orientation according to anotherembodiment of the invention;

FIG. 8 is an exploded view of another antenna structure including adielectric spacer according to a further embodiment of the presentinvention;

FIG. 9 is a cross-sectional diagram of the antenna structure of FIG. 8;and

FIG. 10 is a flow diagram of a method of providing an antenna structurefor a mobile phone according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram illustrating a communication systemthat includes circuit devices and network elements and operationthereof. More specifically, a plurality of network service areas 04, 06and 08 are a part of a network 10. Network 10 includes a plurality ofbase stations or access points (APs) 12-16, a plurality of wirelesscommunication devices 18-32 and a network hardware component 34. Thewireless communication devices 18-32 may be laptop computers 18 and 26,personal digital assistants 20 and 30, personal computers 24 and 32and/or mobile telephones 22 and 28.

The base stations or APs 12-16 are operably coupled to the networkhardware component 34 via local area network (LAN) connections 36, 38and 40. The network hardware component 34, which may be a router,switch, bridge, modem, system controller, et cetera, provides a widearea network connection 42 for the communication system 10 to anexternal network element. Each of the base stations or access points12-16 has an associated antenna or antenna array to communicate with thewireless communication devices in its area. Typically, the wirelesscommunication devices 18-32 register with the particular base station oraccess points 12-16 to receive services from the communication system10. For direct connections (that is, point-to-point communications),wireless communication devices communicate directly via an allocatedchannel.

Some or all of the wireless communication devices 18-32 may include a FMtransceiver to receive and/or transmit continuous waveform signals inthe FM frequency broadcast band, which in the United States is 87.9 to107.9 MHz. It can be appreciated, however, that FM may be transmitted onany frequency. In the present example, wireless communication devices22, 24, 28, 30, and 32 include FM transceivers 23, 25, 31, 33, and 35,respectively. In this manner, the wireless communication devices mayreceive and/or transmit media content via FM frequency transmissiontechniques.

In addition to media content (such as audio, video, et cetera), awireless communication device may receive and/or transmit additionalinformation such as Radio Data System (“RDS”) information, whichprovides small amounts of digital information via FM radio broadcasts.This information can include items such as time, track/artistinformation, station identification, et cetera.

FM broadcast stations 54 and 56 transmit media content over continuouswaveforms in the FM band, in which the FM transceivers 23-33 receive viatheir respective FM antennas. The FM transceivers then process thesignals for playback of the media content to a user device. Also, thewireless communication devices may transmit FM signals as a localbroadcast to nearby audio devices having FM receivers, such as personalstereos, automobile FM radios, et cetera.

The small wireless devices receive correspondingly-sized FM antennashaving an antenna structure, which improves the antenna performanceacross non-ideal environmental conditions for the small wireless device.In general, a human body proximate to an FM antenna affects theimpedance of the FM antenna (such as the wireless device being claspedin a user's hand, stored in a pocket, notebook, et cetera). As a personmoves either closer to or further away from an antenna, the change inthe relative position of the person proximate to the antenna causes theimpedance of the antenna to change. A human body also absorbs the radiofrequency waves, affecting the electric field and the magnetic field ofthe RF wave. Because the FM antennas are reduced to fit within a smallerwireless device, the antenna impedances become more sensitive to thesevarying environmental conditions.

As a result, the varying antenna impedances resulting from the non-idealenvironmental conditions affect the signal processing and media contentplayback to a user. For example, when reception conditions are less thanideal (that is, the signal-to-noise ratio worsens), a stereo FMbroadcast playback is in mono, or the FM signal may be droppedaltogether. With ever varying environmental conditions, the varyingand/or inconsistent playback frustrates users. These antenna structuresare discussed in greater detail with reference to FIGS. 2 through 10.

FIG. 2 is a schematic block diagram illustrating a wirelesscommunication device 22-32. As illustrated, wireless communicationdevice 22-32 includes a digital processing module 54, a memory 56, userinterface(s) 52, transceivers 58-66, an FM antenna tuning module 68, aprinted FM antenna 70, and the antenna switch 72. The digital processingmodule 54 and memory 56 execute instructions and perform correspondingcommunication functions in accordance with a particular mobile and/orcellular phone standard.

User interface(s) 52 allows data to be received from and providesconnectivity to an output device such as a display, monitor, speakers,microphone, et cetera, such that the received data may be displayedand/or presented. The digital processing module 54 may also receive theoutbound data from an input device such as a keyboard, keypad,microphone, et cetera, via the user interface(s) 52 or generate the dataitself. The user interface provides outbound data 76 to the digitalprocessing module 54 for transmission via one of the transceivers 58-66.The user interface also receives inbound data 74 destined for a user.

The wireless communication device 22-32 includes several transceivers(that is, receiver and transmitter) for accommodating differentcommunication and/or data sessions. The wireless communication device22-32 includes a cellular transceiver 58 (for example, PersonalCommunication System (PCS), Global System for Mobile Communications(GSM), Wideband CDMA, et cetera), a Wireless Wide Area Network (WWAN)transceiver 60 (for example, WiMAX, HSDPA, et cetera), a Wireless LAN(WLAN) transceiver 62 (for example, IEEE 802.11), a Wireless PersonalArea Network (WPAN) transceiver 64 (for example, Bluetooth, IEEE 802.15,et cetera), and a FM transceiver 66.

The transmitter portion of a transceiver generally includes a datamodulation stage, one or more intermediate frequency stages, and a poweramplifier stage. The data modulation stage converts raw data intobaseband signals in accordance with the particular wirelesscommunication standards specification. The one or more intermediatefrequency stages mix the baseband signals with one or more localoscillations to produce RF signals. The power amplifier stage amplifiesthe RF signals prior to transmission via an antenna.

A transceiver receiver portion generally includes a low noise amplifier(LNA) stage, one or more intermediate frequency stages, and a datademodulation stage. The LNA stage amplifies the received RF signals forproviding a stronger signal for subsequent processing. The one or moreintermediate frequency stages mix the RF signals with one or more localoscillations to produce baseband signals, in accordance with theparticular wireless communication standards specification. In othertransceiver configurations, a received FM signal may be converteddirectly to baseband signals. The data demodulation stage operates toconvert the baseband signals into raw data.

The transceivers 58-64 receive and transmit RF signals via the antennaswitch 72, which operates to couple the receivers to the antenna 86 in areceive mode, and to couple the transmitters in a transmit mode. Theantenna switch 72 provides a many-to-one access to the antenna 86 forproviding efficient use of antenna resources. Examples of antennaswitches are discussed in further detail in U.S. Pat. No. 7,079,816,entitled “On Chip Diversity Antenna Switch,” issued Jul. 18, 2006, whichis hereby incorporated herein by reference.

The FM transceiver 66 receives continuous waveform signals 89 from an FMtransmitter, such as FM broadcast stations 54 and 56 (see FIG. 1), viathe printed FM antenna 70. Also, the FM transceiver 66 may transmit acontinuous waveform signal 89 in the FM band to a local receiver (suchas a personal stereo, automobile FM radio, et cetera).

An FM antenna tuning module 68, including a tuning circuit 69, operatesto adjust the impedance match with the printed FM antenna 70 with animpedance adjustment value 73. In general, the smaller the “footprint”of an FM antenna, the more vulnerable its performance is due to itspositioning within a wireless communication device with respect to othercomponents, and more sensitive to changes in its operational environmentthat adversely affect the tuning of the antenna 70 (such as by thevarying proximity of a user to the wireless communication device).

The printed FM antenna 70 may be provided under a variety ofconfigurations, such as a monopole antenna, a dipole antenna (forexample, such as the dipole antenna depicted in U.S. Pat. No. 7,034,770,entitled “Printed Dipole Antenna,” issued Apr. 25, 2006, which is herebyincorporated herein by reference), an eccentric spiral antenna (forexample, such as the eccentric spiral antenna depicted in U.S. Pat. No.6,947,010, entitled “Eccentric Spiral Antenna,” issued Apr. 4, 2000,which is hereby incorporated herein by reference), a fractal elementantenna, et cetera. Each configuration may have different designconsiderations.

As an example, a monopole antenna may have improved performance over adipole antenna structure due to the lower ohmic loss of the antennatraces (that is, less antenna traces can be used with a monopolestructure). In general, a lower ohmic loss provides the printed FMantenna 70 with higher antenna efficiency.

The monopole structure relies on the existing ground of the mobile phone22 to generate an image of the “missing” portion (that is, the “dipole”portion for the monopole antenna). Because the wireless device may nothave a perfect ground available for attachment of a monopole antennastructure, the impedance matching may be unpredictable. The overallperformance of a monopole antenna, however, may improve due to the lowerohmic loss of the antenna trace 218 with respect to small antenna“footprints”.

Lower ohmic loss for an antenna may also be recognized by operating anantenna at a higher resonant frequency. For example, the printed FMantenna 70 has a higher resonant frequency (such as 2-3 times higher)than the intended operational frequency (in the present example, the FMfrequency band). The higher resonant frequency permits the electricallength of the antenna to be reduced, and correspondingly, the amount ofspace allocated for the antenna trace. That is, a shorter electricallength has fewer trace windings that can have larger trace surfaces in agiven antenna area—the result is a lower ohmic loss. In operation withthe FM transceiver 66 can then reduce the resonant frequency of theprinted FM antenna 70 to the intended frequency resonance using discrete(or lumped) low-loss antenna matching components.

A trade off, however, exists between the highest resonant frequency towhich the antenna is tuned versus the amount of impedance matching (viathe FM antenna tuning module 68) to bring the resonant frequency withinthe desired operational frequency. For instance, when the antennaresonates at a very high frequency, the required amount of impedancematching is excessive, consequently producing excessive antenna loss. Inother words, the advantage of having a lower ohmic loss and higherantenna efficiency is lost. On the other hand, when the antennaresonates substantially close to the desired resonant frequency, littlematching components would be needed, but the resulting ohmic loss of theresulting FM antenna trace would be comparable or larger than theradiation resistance for the FM antenna 70.

The FM antenna tuning module 68 operates to tune the printed FM antenna70 within the desired operational frequency. The FM antenna tuningmodule 68, based upon a signal strength indication of a receivedcontinuous wavelength signal 89, provides an adjustment control signalto the tuning circuit 69. The tuning circuit 69 correspondingly variesthe impedance (and the resonance frequency) of the printed FM antenna 70via an impedance adjustment value 73. The tuning circuit 69 includesvoltage-controlled variable impedance devices (such as varactors orvaricap diodes) to produce the impedance adjustment value 73. That is,by adjusting the impedance value through the tuning circuit 69, the FMantenna tuning module 68 tunes the printed FM antenna 70 to theoperational conditions of the wireless communication device 22-32.

The FM antenna tuning module 68 has at least two tuning modes: afrequency recovery mode and a tracking tuning mode.

Under the first mode, the FM antenna tuning module 68 enters thefrequency recovery mode either upon startup of the wireless device, orupon a complete loss of an FM signal (such as when entering anunderground tunnel). In the frequency recovery mode, the tuning module68 operates to establish a stronger FM signal by centering the frequencyof the printed FM antenna 70 based upon a signal strength indication.When an FM signal is established (as reflected by the signal strengthindication), the tuning module 68 determines the frequency associatedwith the selected FM antenna tuning. Based upon a delta frequency valuefor a desired FM channel versus a known FM channel, the tuning module 68modifies the tuning of the antenna via the tuning circuit 69 to producethe impedance adjustment value 73.

Under the second, or tracking, mode, the tuning module 68 continuouslytracks variations of the signal such as those caused by changes in thedevice's environment, which may cause the FM antenna tuning to vary at aslow rate (for example, less than 10 kHz). The tracking function of thetuning module 68 operates to dither the antenna tuning at incrementalsteps (for example, about 0.2 MHz steps) and sampling the continuouswaveform signal strength at the dithered frequency. The dither rate isone outside the range of a user hearing range (for example, about 20 Hzto about 20 kHz) to minimize audible detection of the operation by auser.

The FM antenna tuning module 68 and the tuning circuit 69 may be on asingle integrated circuit or a plurality of integrated circuits. Also,the FM antenna tuning module and the tuning circuit 69 may beimplemented as part of a system on a chip. Examples of otherimplementations are discussed in detail with reference to FIG. 3. Adiscussion of the antenna structures are discussed in further detailwith reference to FIGS. 4 through 10.

The digital processing module 54, in combination with operationalinstructions stored in memory 56, executes digital receiver andtransmitter functions. The digital processing module 54 may beimplemented using a shared processing device, individual processingdevices, or a plurality of processing devices. Such a processing devicemay be a microprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on operational instructions.

Memory 56 may be a single memory device or a plurality of memorydevices. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, and/or any device that stores digital information.Note that when digital processing module 54 implements one or more ofits functions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory storing the corresponding operationalinstructions is embedded with the circuitry comprising the statemachine, analog circuitry, digital circuitry, and/or logic circuitry.Memory 56 stores, and digital processing module 54 executes, operationalinstructions corresponding to at least some of the functions illustratedand/or described herein.

In operation, the digital processing module 54 processes outbound data76 in accordance with a particular wireless communication standard (forexample, IEEE 802.11a, IEEE 802.11b, Bluetooth, IEEE 802.16, et cetera)to produce the appropriate digital transmission formatted data for apresent communication session, which includes cellular data 59, WLANdata 61, WWAN data 65, and/or FM signal data 67. This data will be adigital baseband signal or a digital low IF signal, where the low IFtypically will be in the frequency range of one hundred kilohertz to afew megahertz.

Each respective transceiver 58-66 converts the digital data from thedigital domain to the analog domain. Though the antenna 86 isschematically depicted as external to the body of the radio, commercialversions of the wireless communication device generally incorporate theantenna element and structures within the body of the device. Also, thewireless communication device may also include additional antennas forstandards specific applications, such as those for Bluetoothapplications, et cetera.

As one of average skill in the art will appreciate, the wirelesscommunication device of FIG. 2 may be implemented using one or moreintegrated circuits. For example, the digital processing module 54 andmemory 56 may be implemented on a second integrated circuit, and theremaining components of the wireless communication device 22-32, lessantenna 86, may be implemented on a third integrated circuit. As analternate example, the wireless communication device 22-32 may beimplemented on a single integrated circuit.

FIG. 3 is a schematic block diagram illustrating a wirelesscommunication device 22-32 that includes a distributed embodiment of theFM antenna tuning module 68 and the tuning circuit 69, and multipleantenna switches 75 and 76 coupled to the antennae 86.

As illustrated, the wireless communication device 22-32 includes adigital processing module 54 and a memory 56. The digital processingmodule 54 and memory 56 execute instructions and perform correspondingcommunication functions in accordance with a particular mobile and/orcellular phone standard. To the extent that like components and/orelements have been earlier described of the wireless communicationdevice 22-32, the description will not be repeated here with respect toFIG. 3.

The wireless communication device 22-32 includes antenna switch 75 andantenna switch 77. Antenna switch 75 services the cellular Tx/Rx signal81 and the WWAN Tx/Rx signal 83 for transmission and/or reception modesover the antenna 86. Antenna switch 77 services the WLAN Tx/Rx signal 85and WPAN Tx/Rx signal 87 for transmission and/or reception modes overthe antenna 86. The FM transceiver 66 receives and/or transmits acontinuous wavelength signal 89 via the printed antenna 70.

Multiple antenna switches 75 and 77 permit each of the antenna switchesto accommodate the characteristics of similar communications modes.Examples of characteristics may include similar frequency bands, similardata rates, et cetera. For example, an antenna switch may servicecellular frequency bands (such as for AMPS, IS-95 (CDMA), IS-136(D-AMPS), GSM, operating in the 824-849 MHz, 869-894 MHz, 896-901 MHz,and 935-940 MHz frequency bands), and another antenna switch may servicePersonal Communication Service (“PCS”) frequency bands (such as for GSM,IS-95 (CDMA), IS-136 (D-AMPS), operating in the 1850-1910 MHz and1930-1990 MHz frequency bands). A further antenna switch may servicehigh-data rate communications (such as 2.4 GHz).

The FM transceiver 66 receives from the printed FM antenna 70 thecontinuous wavelength signal 89 via the printed FM antenna 70. The FMantenna tuning module 68 receives from the FM transceiver 66 a signalstrength indication (SSI). When the SSI falls outside a permissiblesignal strength level, the tuning circuit 69 provides an impedanceadjustment value 73 to the printed FM antenna based upon the tuning data71 from the FM antenna tuning module 68.

The tuning circuit 69 is illustrated as provided on a separate IC withrespect to the FM transceiver 66 and the FM antenna tuning module 68. Inthis manner, differing fabrication processes may be used to implementthe voltage-controlled variable impedance devices of the tuning circuit69 and with processes to implement other components of the wirelesscommunication device 22-32. That is, in some instances, a reduction infabrication cost and complexity may be realized. Also, wirelesscommunication devices may have an impedance bank accessible to othercomponents within the device to permit shared access to those components(for example, for clock adjustment, et cetera). By adjusting theimpedance value of the tuning circuit 69, the FM antenna tuning module68 times the printed FM antenna 70 to an impedance of a communicationsdevice 22-32.

FIG. 4 is an exploded view of a mobile phone 22 having an antennastructure 200. The mobile phone 22 has a structure sometimes referred toas a “brick.” The mobile phone 22 includes a case face cover 202, a caseback cover 222, and a battery cover 228. The case face cover 202includes a display 204, a function keypad 206, and a numeric keypad 208.The case face cover 202 receives a printed circuit board 210 havingintegrated circuits 212, which include transceivers 58-66 (such as thatdiscussed with reference to FIGS. 2 and 3) that is coupled to a printedFM antenna 70 of the antenna structure 200.

Further, the printed circuit board 210 may include lumped tuningcomponents to initially match the impedance of the mobile phone 22 withthe printed FM antenna 70. The case back cover 222 includes a first side219 and a second side 221. The second side 221 defines a sloped portion223 to receive the battery cover 228.

The mobile phone 22 supports different forms of communication andinformation and/or media content. For example, in addition to supportingvoice calls, the mobile phone 22 can also send and receive data, sendtext messages via a Short Messaging Service (“SMS”), access WirelessApplication Protocol (“WAP”) services, provide Internet access throughdata technologies such as General Packet Radio Service (“GPRS”), sendingand receiving pictures with built-in digital cameras, video and soundrecording, et cetera. Additionally, local features may be available withthe mobile phone 22 such as alarms, volume control, user defined anddownloadable ring tones and logos, interchangeable covers, et cetera.

The antenna structure 200 includes the printed FM antenna 70, aconductive material forming a ground plane 224, and the battery 226. Theprinted FM antenna 70 includes an antenna trace 218, and an input/outputconnection 216. The printed FM antenna 70 has a planar structure that isless than a planar area of the battery cover 228, and is positionedadjacent the inside of the battery cover 228. The printed FM antenna 70may have a variety of configurations that are designed according tovarying criteria, as discussed with respect to FIG. 2.

Also, the printed FM antenna 70 may be implemented on one or moreprinted circuit board layers and/or one or more integrated circuitlayers. The coupling of the transceiver circuitry of the integratedcircuits 212 with the printed FM antenna 70 may be direct or indirectand positioned on the printed FM antenna 70 to achieve a desired loadimpedance. For example, the input/output connection 216 may be a coaxialprobe, a printed microstrip, a waveguide, and a coplanar transmissionline, et cetera.

A battery 226 has a planar structure and is positioned adjacent a secondside of the ground plane 224, such that the planar structure of theprinted antenna 70 and of the battery 226 are substantially parallel.The ground plane 224, which is positioned between the battery 226 andthe printed FM antenna 70, operates to improve a signal-to-noiseperformance of the printed FM antenna 70. The battery 226 may have aconductive outer layer that provides the ground plane 224 to the printedFM antenna 70. The battery cover 228, case back cover 222, and the caseface cover 202 couple to provide the electrical and physicalconnectivity for operation of the mobile phone 22.

FIG. 5 is an exploded view of a mobile phone 28 having an antennastructure 200. The mobile phone 28 has a structure sometimes referred toas a “clamshell” structure. The mobile phone 28 supports different formsof communication and media information content. For example, in additionto supporting voice calls, the mobile phone 28 can also send and receivedata, send text messages via a Short Messaging Service (“SMS”), accessWireless Application Protocol (“WAP”) services, provide Internet accessthrough data technologies such as General Packet Radio Service (“GPRS”),sending and receiving pictures with built-in digital cameras, video andsound recording, et cetera. Additionally, local features may beavailable with the mobile phone 28 such as alarms, volume control, userdefined and downloadable ring tones and logos, interchangeable covers,et cetera.

The mobile phone 28 includes a first portion 242 and a second portion250. The first portion 242 includes a keypad 244, a function keypad 246,and a case face cover 254. The first portion 242 also receives a printedFM antenna 70, and a battery 226, each of which being separated by aground plane 224. The battery 226, ground plane 224, and the printed FMantenna 70 may be formed as a unit with the back cover 229. The secondportion 250 of the mobile phone 28 includes a display 248 for relayingcall status and other information that may be retrieved and presented tothe user. The first portion 242 and the second portion 250 fold along ahinge portion 251 to a substantially parallel position when placed in aclosed position.

The mobile phone 28, via the first portion 242, receives a printedcircuit board 210 having integrated circuits 212, which includetransceiver circuitry 58-66 (such as that discussed with reference toFIGS. 2 and 3). The FM transceiver 66 (see FIGS. 2 and 3) is coupled tothe printed FM antenna 70.

The first portion 242 of the clamshell structure provides a smallerfootprint space and/or area for the printed FM antenna 70. Accordingly,the performance of the printed FM antenna is more readily influenced bychanges in its operational environment by impedance changes caused by auser and/or other objects. In this regard, the ground plane 224 servesto mitigate these influences and to further improve the performance ofthe printed FM antenna with respect to signal reception. Also, theprinted circuit board may include lumped tuning components, whichcompensate for impedances introduced by the mobile phone components,initially tuning the printed FM antenna 70 to the wireless communicationdevice 22-32.

The printed FM antenna 256 includes an antenna trace 252, and aninput/output connection 258. The printed FM antenna 70 has a planarstructure that is less than a planar area of the first portion 242 ofthe phone 28, and is positioned adjacent the ground plane 224. Theprinted FM antenna 70 may be implemented on one or more printed circuitboard layers and/or one or more integrated circuit layers. The couplingof the transceiver circuitry of the integrated circuits with the printedFM antenna 70 may be direct or indirect, and positioned on the printedFM antenna 70 to achieve a desired load impedance. For example, theinput/output connection 216 may be a coaxial probe, a printedmicrostrip, a waveguide, and a coplanar transmission line, et cetera.

The printed FM antenna 70 may be provided under a variety ofconfigurations depending upon the desired operational characteristics.Examples of the varying configurations are discussed in detail withrespect to FIG. 2.

The battery 226 has a planar structure that is positioned adjacent asecond side of the ground plane 224, such that the planar structure ofthe printed FM antenna 70 and of the battery 226 are substantiallyparallel to each other in a spaced apart relation to improve theperformance of the printed FM antenna 70. The battery 226, ground plane224, printed FM antenna 70, and back cover 229 may be integrated into amodule that detachably couples with the first portion 242 to provide theelectrical and physical connectivity for operation of the mobile phone28. Further, the ground plane 224 may be formed as a conductive layer tothe battery 226.

FIG. 6 is a cross-sectional diagram of the antenna structure 200. Theantenna structure 200 includes the printed FM antenna 70 and the battery226 with the ground plane 224 in a layered relation. The antenna trace218 is electrically insulated from the ground plane 224 by a protectivelayer 225. The printed FM antenna 70 has a planar structure that is lessthan a planar area defined by the outer periphery of the mobile phonebattery cover 228, and is positioned such that the antenna substrate 219is adjacent the inner side of the battery cover 228. The antenna trace218 is oriented towards the ground plane 224.

The antenna substrate 219 may be formed with the battery cover 288, andfurther may be coupled to, or form a portion of, the inner surface ofthe battery cover 228. The protective layer 225 and the antennasubstrate 219 are made of a dielectric material that provides electricalinsulation between mobile phone components while supportingelectrostatic fields. Further, the dielectric material has a dielectricconstant sufficient to concentrate electrostatic lines of flux whiledissipating minimal energy in the form of heat. Examples of materialsinclude air, polyethylene, polystyrene, et cetera. The planar structureof the printed FM antenna 70, the ground plane 224, and the planarsurface of the battery 226 are substantially parallel to each other. Thesandwiched structure provides improved FM signal reception for theprinted FM antenna 70.

FIG. 7 is a cross-sectional diagram of the antenna structure 239. Theantenna structure 239 illustrates another sandwich structure that may beused in the mobile phones 22 and/or 28. The antenna structure 200includes the printed FM antenna 70 and the battery 226 with the groundplane 224 in a layered relation. The antenna trace 218 is electricallyinsulated and/or mechanically protected by a protective layer 225. Theprinted FM antenna 70 has a planar structure that is less than a planararea defined by the outer periphery of the mobile phone battery cover228, and is positioned such that the antenna substrate 219 is adjacentthe ground plane 224. The antenna trace 218 is adjacent the innersurface of the battery cover 228. Accordingly, The planar structure ofthe printed FM antenna 70, the ground plane 224, and the planar surfaceof the battery 226 are substantially parallel to each other. Thesandwiched structure provides improved FM signal performance for theprinted FM antenna 70.

FIG. 8 is an exploded view of a further antenna structure 230implementing a dielectric spacer 257. The antenna structure 230 may beused in the brick structure of the mobile phone 28 and/or the clamshellstructure of the mobile phone 28, as well as other suitable wirelessdevice structures.

The antenna structure 230 includes the printed FM antenna 70 and thebattery 226 in a spaced-apart relation via a dielectric spacer 257. Thedielectric spacer 257 includes a first dielectric spacer portion 260 anda second dielectric spacer portion 262. The dielectric spacer 257 alsoincludes web portions 261 that space the first and dielectric spacerportion 260 and 262 in a fixed relation, providing a first side 263 anda second side 265. The dielectric spacer 257 provides further separationbetween the battery 226 and the printed FM antenna 70, which services toimprove the E-M flux characteristics of the printed FM antenna, andimproves the performance of the printed FM antenna 70.

The dielectric spacer 257 has different dielectric constants that areattributed to the components of the dielectric spacer 257 and the cavity259 defined therein, which may be “filled” with air from the surroundingenvironment. Also, the dielectric space 257 may be formed of a similarmaterial throughout, or formed with multiple materials with differentdielectric properties.

In this manner, the dielectric spacer 257 provides electrical insulationbetween the printed FM antenna 70 and mobile phone components, whilealso supporting electrostatic fields. In general, the area of thedielectric spacer 257 substantially corresponds to the surface area ofthe printed FM antenna 70; however, dielectric spacers with smallersurface areas may also be used while the desired improvement to theperformance of the printed antenna 256 is realized.

The printed FM antenna 70 has a planar structure less than a planar areadefined by the outer periphery of the battery cover 228, and ispositioned adjacent the inner surface of the mobile phone battery cover228. The battery 226 has a planar surface positioned adjacent the groundplane 224, which may be a conductive outer layer of the battery 226. Theconductive outer layer of the battery 226 may partially encase thebattery 226 such that the ground plane 224 is positioned between thebattery 226 and the printed FM antenna 70. The sandwiched antennastructure 230 provides improved FM signal performance for the printed FMantenna 70.

FIG. 9 is a cross-sectional diagram of the antenna structure 230 of FIG.8 with the dielectric spacer 257 and a gap 231 between the antennastructure 230 and the battery cover 228.

The antenna structure 230 includes the printed FM antenna 70 and thebattery 226 in a spaced-apart relation via the dielectric spacer 257.The printed FM antenna 70 has a planar structure generally correspondingto the dielectric spacer 257 and a conductive layer that provides theground plane 224. The printed FM antenna 70 has a protective layer 225and an antenna trace 218, which face adjacent to a first side of thedielectric spacer 257. A conductive layer forming a ground plane 224 ispositioned adjacent a second side of the dielectric spacer 257, and thebattery 226 is in turn adjacent the ground plane 224.

In this manner, the planar structure of the printed FM antenna 70 andthe planar surface of the battery 226 are substantially parallel to eachother in a spaced-apart relation, which serves to improve the FMperformance of the printed FM antenna 70. Further, the gap 231 providesa further dielectric effect with respect to the antenna structure 230,in that a level of electrical insulation between the antenna structure231 and the case covers is provided while supporting electrostaticfields conducive to FM antenna operation.

FIG. 10 is a flow diagram of a method 320 of providing an antennastructure to a mobile phone. Beginning at step 322, a dielectric spacerhaving a first side and a second side is provided to the mobile phone. Aprinted FM antenna having a planar structure is positioned, at step 324,adjacent the first side of the dielectric spacer. At step 326, a batteryhaving a planar surface is positioned adjacent the second side of thedielectric spacer such that the planar structure of the printed FMantenna and the planar structure of the battery are substantiallyparallel to each other in a spaced apart relation. At step 328, aconductive material is positioned between the printed FM antenna and thebattery to provide a ground plane to the printed FM antenna. Theinstallation of the antenna structure increases the FM performance ofthe printed antenna, and correspondingly, improves the performance ofthe wireless communication device in adverse environmental conditions.

As one of average skill in the art will appreciate, the term“substantially” or “approximately”, as may be used herein, provides anindustry-accepted tolerance to its corresponding term. Such anindustry-accepted tolerance ranges from less than one percent to twentypercent and corresponds to, but is not limited to, component values,integrated circuit process variations, temperature variations, rise andfall times, and/or thermal noise. As one of average skill in the artwill further appreciate, the term “coupled”, as may be used herein,includes direct coupling and indirect coupling via another component,element, circuit, or module where, for indirect coupling, theintervening component, element, circuit, or module does not modify theinformation of a signal but may adjust its current level, voltage level,and/or power level. As one of average skill in the art will alsoappreciate, inferred coupling (that is, where one element is coupled toanother element by inference) includes direct and indirect couplingbetween two elements in the same manner as “coupled”. As one of averageskill in the art will further appreciate, the term “compares favorably”,as may be used herein, indicates that a comparison between two or moreelements, items, signals, et cetera, provides a desired relationship.For example, when the desired relationship is that a first signal has agreater magnitude than a second signal, a favorable comparison may beachieved when the magnitude of the first signal is greater than that ofthe second signal or when the magnitude of the second signal is lessthan that of the first signal. While the transistors or switches in theabove described figure(s) is/are shown as field effect transistors(FETs), as one of ordinary skill in the art will appreciate, thetransistors may be implemented using any type of transistor structureincluding, but not limited to, bipolar, metal oxide semiconductor fieldeffect transistors (MOSFET), N-well transistors, P-well transistors,enhancement mode, depletion mode, and zero voltage threshold (VT)transistors.

1. A mobile phone with a FM antenna structure having improvedperformance, the mobile phone comprises: a printed FM antenna having aplanar structure less than a planar area defined by an outer peripheryof the mobile phone; a conductive layer providing a ground plane to theprinted FM antenna, the conductive layer adjacent the printed FM antennain an electrostatic field relation; and a battery having a planarsurface positioned adjacent an opposite side of the conductive layer,wherein the planar structure of the printed FM antenna and the planarsurface of the battery are substantially parallel to each other in aspaced-apart relation improving performance of the printed FM antenna.2. The mobile phone of claim 1 further comprises: a printed circuitboard having integrated circuits including transceiver circuitry coupledto the printed FM antenna, the printed circuit board adjacent thebattery.
 3. The mobile phone of claim 2 wherein the integrated circuitsfurther comprise: lumped tuning components dependent upon the relationof the printed FM antenna to the battery, wherein the lumped tuningcomponents define an impedance bringing the printed FM antenna into anoperational FM band.
 4. The mobile phone of claim 2 wherein the printedFM antenna further comprises: an input/output connection coupled to thetransceiver circuitry.
 5. The mobile phone of claim 4 wherein theinput/output connection comprises at least one of: a coaxial probe, aprinted microstrip, a waveguide, and a coplanar transmission line. 6.The mobile phone of claim 1 wherein the printed FM antenna comprises atleast one of a monopole, a dipole, an eccentric spiral and a fractalantenna.
 7. The mobile phone of claim 1 wherein the conductive layerpartially encases the battery between the planar structure of theprinted FM antenna and the planar surface of the battery.
 8. The mobilephone of claim 1 wherein the mobile phone case comprises: a clamshellstructure having a first portion and a second portion coupled by a hingeportion, the first portion including the mobile phone case back cover,the printed FM antenna, the conductive layer, and the battery, thesecond portion including a display, wherein the first portion and thesecond portion fold to a substantially parallel position when in aclosed position.
 9. The mobile phone of claim 1 wherein the printed FMantenna comprises: an antenna substrate having a dielectric property; anantenna trace printed onto a planar surface of the antenna substrate;and a protective layer encapsulating the antenna trace, wherein theplanar surface of the antenna substrate having the antenna trace isoriented towards the ground plane.
 10. A mobile phone with a FM antennastructure having improved signal-to-noise performance, the mobile phonecomprises: a dielectric spacer having a first side and a second side; aprinted FM antenna having a planar structure positioned adjacent thefirst side of the dielectric spacer; a conductive layer providing aground plane adjacent the second side of the dielectric spacer; and abattery having a planar surface positioned adjacent the conductivelayer, wherein the planar structure of the printed FM antenna and theplanar surface of the battery are substantially parallel to each otherin a spaced apart relation.
 11. The mobile phone of claim 10 furthercomprises: a printed circuit board having integrated circuits includingtransceiver circuitry coupled to the printed FM antenna, the printedcircuit board adjacent the battery.
 12. The mobile phone of claim 11wherein the integrated circuits further comprise: lumped tuningcomponents dependent upon the relation of the printed FM antenna to thebattery, wherein the lumped tuning components define an impedancebringing the printed FM antenna into an operational FM band.
 13. Themobile phone of claim 11 wherein the printed FM antenna furthercomprises: an input/output connection coupled to the transceivercircuitry.
 14. The mobile phone of claim 13 wherein the input/outputconnection comprises at least one of: a coaxial probe, a printedmicrostrip, a waveguide, and a coplanar transmission line.
 15. Themobile phone of claim 10 wherein the printed FM antenna comprises atleast one of a monopole, a dipole, an eccentric spiral and a fractalantenna.
 16. The mobile phone of claim 10 wherein the conductive layerpartially encases the battery.
 17. The mobile phone of claim 10 whereinthe mobile phone comprises: a clamshell structure having a first portionand a second portion, the first portion including the printed FMantenna, the conductive layer, the dielectric spacer, and the battery,the second portion including a display, wherein the first portion andthe second portion fold to a substantially parallel position when placedin a closed position.
 18. The mobile phone of claim 10 wherein theprinted FM antenna comprises: an antenna substrate having a dielectricproperty; an antenna trace printed onto a planar surface of the antennasubstrate; and a protective layer encapsulating the antenna trace,wherein the planar surface of the antenna substrate having the antennatrace is oriented towards the ground plane.
 19. A mobile phone with a FMantenna structure having improved FM performance, the mobile phonecomprises: a clamshell structure having a first portion coupled to asecond portion, wherein the first portion and the second portion fold toa substantially parallel position when placed in a closed position,wherein the first portion includes: a printed FM antenna having a planarstructure less than a planar area of the mobile phone a conductive layerproviding a ground plane to the printed FM antenna, the conductiveadjacent the printed FM antenna in an electrostatic field relation; anda battery having a planar surface positioned adjacent an opposite sideof the conductive layer, wherein the planar structure of the printed FMantenna and the planar surface of the battery are substantially parallelto each other in a spaced-apart relation improving performance of theprinted FM antenna.
 20. The mobile phone of claim 19 wherein the firstportion of the clamshell structure further comprises: a printed circuitboard having integrated circuits including transceiver circuitry coupledto the printed FM antenna, the printed circuit board adjacent thebattery.
 21. The mobile phone of claim 20 wherein the integratedcircuits further comprise: lumped tuning components dependent upon therelation of the printed FM antenna to the battery, wherein the lumpedtuning components define an impedance bringing the printed FM antennainto an operational FM band.
 22. The mobile phone of claim 19 whereinthe printed FM antenna further comprises: an input/output connectioncoupled to the transceiver circuitry.
 23. The mobile phone of claim 22wherein the input/output connection comprises at least one of: a coaxialprobe, a printed microstrip, a waveguide, and a coplanar transmissionline.
 24. The mobile phone of claim 19 wherein the printed FM antennacomprises at least one of a monopole, a dipole, an eccentric spiral anda fractal antenna.
 25. The mobile phone of claim 19 wherein theconductive layer partially encases the battery.
 26. The mobile phone ofclaim 19 wherein the printed FM antenna comprises: an antenna substratehaving a dielectric property; an antenna trace printed onto a planarsurface of the antenna substrate; and a protective layer encapsulatingthe antenna trace, wherein the planar surface of the antenna substratehaving the antenna trace is oriented towards the ground plane.
 27. Amobile phone with an FM antenna structure having improved FMperformance, the mobile phone comprises: a clamshell structure having afirst portion coupled to a second portion, wherein the first portion andthe second portion fold to a substantially parallel position when placedin a closed position, wherein the first portion includes: a dielectricspacer having a first side and a second side; a printed FM antennahaving a planar structure positioned adjacent the first side of thedielectric spacer; a conductive layer providing a ground plane adjacentthe second side of the dielectric spacer; and a battery having a planarsurface positioned adjacent the conductive layer, wherein the planarstructure of the printed FM antenna and the planar surface of thebattery are substantially parallel to each other in a spaced apartrelation.
 28. The mobile phone of claim 27 further comprises: a printedcircuit board having integrated circuits including transceiver circuitrycoupled to the printed FM antenna, the printed circuit board adjacentthe battery.
 29. The mobile phone of claim 28 wherein the integratedcircuits further comprise: lumped tuning components dependent upon therelation of the printed FM antenna to the battery, wherein the lumpedtuning components define an impedance bringing the printed FM antennainto an operational FM band.
 30. The mobile phone of claim 27 whereinthe printed FM antenna further comprises: an input/output connectioncoupled to the transceiver circuitry.
 31. The mobile phone of claim 30wherein the input/output connection comprises at least one of: a coaxialprobe, a printed microstrip, a waveguide, and a coplanar transmissionline.
 32. The mobile phone of claim 27 wherein the printed FM antennacomprises at least one of a monopole, a dipole, an eccentric spiral anda fractal antenna.
 33. A method for providing an antenna structure for amobile phone, the method comprises: providing a dielectric spacer havinga first side and a second side; positioning a printed FM antenna havinga planar structure adjacent the first side of the dielectric spacer;positioning a battery having a planar surface adjacent the second sideof the dielectric spacer, wherein the planar structure of the printed FMantenna and the planar surface of the battery are substantially parallelto each other in a spaced apart relation; and positioning a conductivematerial between the printed FM antenna and the battery to provide aground plane to the printed FM antenna.
 34. The method of claim 33further comprises: coupling transceiver circuitry of a printed circuitboard having integrated circuits including transceiver circuitry to theprinted FM antenna, the printed circuit board adjacent the battery. 35.The method of claim 34 wherein the integrated circuits further comprise:lumped tuning components dependent upon the relation of the printed FMantenna to the battery, wherein the lumped tuning components define animpedance bringing the printed FM antenna into an operational FM band.36. The method of claim 34 wherein the coupling the transceivercircuitry comprises: coupling an input/output connection of the printedFM antenna to the transceiver circuitry.
 37. The method of claim 36wherein the input/output connection comprises at least one of: a coaxialprobe, a printed microstrip, a waveguide, and a coplanar transmissionline.
 38. The method of claim 33 wherein the printed FM antennacomprises at least one of a monopole, a dipole, an eccentric spiral anda fractal antenna.
 39. The mobile phone of claim 33 further comprises:providing a conductive layer to the battery, wherein the conductiveouter layer provides a ground plane to the printed FM antenna.
 40. Themethod of claim 39 wherein the conductive outer layer partially encasesthe battery.